A freeway off-ramp that crosses the canal in Central San Rafael is due for a $17.15 million makeover.

The northbound Highway 101 offramp that feeds freeway traffic onto Irwin and Second streets over San Rafael Creek is considered “inadequate” by Caltrans and is slated for a rebuild starting this spring.

Construction will be broken up into three phases, continuing through spring 2020, Caltrans reported. The project calls for a new bridge, new bridge deck, reconfigured pedestrian crosswalks at Second Street and a second right-turn/through lane onto Second Street.

“We are replacing a bit of infrastructure that is starting to show its age,” said Bob Haus, Caltrans spokesman. “This bridge has been out there for a long time and has reached the end of its service life.”

Haus said there is no way to avoid the inconveniences and traffic backup that will result with closing the offramp. But he said “we want to do it in a way that provides the least amount of inconveniences; the least disruption to people’s lives.”

For that reason, Caltrans planners are considering how to best split up the pile driving work, which is the loudest part of the project and will require full closures of the offramp.

There are three options up for consideration, including 42 nighttime closures from 11 p.m. to 7 a.m.; five full weekend closures with limited pile driving from 7 a.m. to 10 p.m.; or closures over three nonconsecutive weekends over the course of a few months with pile driving around the clock.

During closures, drivers will be re-directed to either to the Bellam Boulevard or North San Pedro Road exits. Equipment will be muffled and noise will be shielded, but work will be loud, especially at night, Caltrans officials said.

To solicit feedback on the preferred method, the city of San Rafael asked residents to participate in an online survey, which closed Nov. 7.

Kevin McGowan, assistant public works director, said the city is compiling the survey responses to pass onto Caltrans.

“We will try to have as much information about this project as we can published on our website,” McGowan said. “Being that this is a Caltrans project, any type of that info is going to broadcast out from them. So we’re going to do what we can to make sure folks know what’s going on.”

Richard Bernstein, who lives in the Lomita Park neighborhood south of downtown San Rafael, said that he and his neighbors “are quite struck that so little has come out about this project to the residents,” adding that not much is known.

“It’s stunning, the effect that something like this will have in San Rafael,” Bernstein said, noting that the offramp is jam-packed during the morning and afternoon commutes. “It’s pretty scary. We will survive, but we are all going through a bit of battle fatigue from the traffic, and this is pretty significant; it’s only going to add to it.”

Gerstle Park resident Amy Likover is chairwoman of the Federation of San Rafael Neighborhoods, a neighborhood advocacy group. She said she was unaware of the project, but has now added a discussion item on the topic to the federation’s next committee meeting.

“At this point, we simply have to get informed,” she said. “The neighborhoods and merchants in the area are so impacted by traffic already.”

Likover said, “we have a lot of concerns about gridlock, and so if this is a project about safety, then of course safety comes first. But if there are going to be other hazards during construction, that has to be looked at, too.”

The project was approved by Caltrans under its Bridge Rehabilitation Program in July 2017. The California Transportation Commission approved construction funding in August 2018. The project is being paid for by the State Highway Operation and Protection Program, or SHOPP, which is being matched by money from the state gas tax, Senate Bill 1. Permitting agencies include the Department of Fish and Wildlife, Regional Water Quality Control Board and the Army Corps of Engineers.

Adrian Rodriguez covers transportation, San Rafael and the Ross Valley for the Marin IJ. He also writes the weekly business column Movers & Shakers, which appears in Friday's paper. Reach the author at arodriguez@marinij.com or follow Adrian on Twitter: @adrianrrodri.